In the past year, outstanding progress was made on all the projects. Project III: New Sertoli cell proteins were isolated and their hormonal response was studied. Monoclonal antibodies against several Sertoli cell products were prepared and used to establish reagents for measuring these proteins. The genes for three extracellular steroid binding proteins [cortisol binding globulin, testosterone estradiol binding globulin, and androgen binding protein (rABP)] were cloned. The cDNA for rABP was used to measure the mRNA in Sertoli cell cultures. Project IV: Transforming growth factor was shown to stimulate Sertoli cell growth to a greater extent than epidermal growth factor (EGF). Alpha-MSH and des acetyl Alpha-MSH, two peptides derived from proopiomelanocortin, were shown to be equally potent as stimulators of cAMP secretion. Monoclonal antibodies to surface proteins on Sertoli cells prevented testicular differentiation in vitro. Project V: The mRNAs for the androgen responsive genes for ornithine decarboxylase were studied in detail. The two dominant mRNA species were shown to be derived from two similar genes with different 5'-ends. The human ODC gene was cloned and sequenced; its derived amino acid sequence has over a 90% homology with the murine gene. Project VI: The androgen responsive genes for mouse kidney Beta-glucuronidase and KAP were studied. The glucuronidase structural gene has been extensively mapped; it has a minimum length of 14 kb and has at least 9 intervening sequences. Renal cell culture systems were established which expressed Beta-glucuronidase and ornithine decarboxylase mRNAs. A radioimmunoassay for KAP was established using a synthetic peptide, the structure for which was derived from the gene sequence. Project VII: Studies were conducted to demonstrate the recovery of fertility in men following vasectomy reversal. Antisperm antibodies in these individuals are believed to correlate with the slow recovery of fertility after this operative procedure. In a cooperative study with the Institute of Immunology in India a vaccine against LHRH was tested in rabbits.